1. Field of the Invention
The present invention relates to a timepiece such as a portable watch, such as a wristwatch and a pocket watch, a desk clock and a wall-mounted clock.
2. Description of the Prior Art
Heretofore among wristwatches having a case back, there is known a wristwatch in which an annular protrusion part is formed in an inner periphery of a front side end part of a case band in which a dial is accommodated, and to the inner periphery of this annular protrusion part there are fitted and fixed a glass covering the dial and fitted a tubular part of an edge member functioning also as a bezel. A caulking part integral with the tubular part is caulked to a back face of the annular protrusion (for example, refer to JP-UM-B-5-37273 Gazette).
In the wristwatch in which the edge member has been caulked to the case band as mentioned above, since the fact that a caulked part having been deformed is caulked again after having been returned to a state before being caulked extremely decreases a mechanical strength of the caulked part, it is impossible to detach the edge member from the case band. For this reason, in a case where the edge member has been impaired, a user of the wristwatch is obliged to exchange not only the edge member to which the glass has been fixed but also to exchange it together with the case band to which this edge member has been caulked.
Further, in a wristwatch in which a waterproofness is achieved by nipping a seal packing between the case band and the edge member, there is considered the fact that a performance of the seal packing decreases during a long period guarantee term of the wristwatch and thereafter. Also in a case where, in order to cope with this, it is attempted to exchange the seal packing, since it is impossible to detach the edge member from the case band, it is necessary to exchange not only the edge member but also to exchange it together with the case band to which the edge member has been caulked.